Introduction Single codestream OpenGIS GML in JPEG 2000 for Geographic Imagery Encoding Specification
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Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved.
Figure 4 — Packaging of GML for a single codestream
The single “outer” association box contains a box-first which is a label box. This shall contain the label “gml.data”.
The outer association box shall contain at least one additional association box containing GML instance data. This association box shall have a box-first that is a label box with the
label gml.root-instance and an XML box. This XML box may only contain GML instance data for the following items:
• Coverage description see Clause 6.1 and 7.1 • Metadata instances see Clause 6.2 and 7.2
• Annotation instances see Clause 6.3 and 7.3 • Feature instances see Clause 6.4 and 7.4
The box labelled gml.root-instance shall not contain XML schemas and shall not contain CRS nor units of measure dictionary instances.
Any number of association boxes may follow the gml.root-instance box. Each of the association boxes, other than the gml.root-instance and gml.data boxes, shall have a label the
box-first shall be a label box in each case. The value of the label is any value allowed by JPEG 2000 Part II. This label is used in references to the XML box content using the
mechanism described in Clause 8.5.
asoc
“gml.data”
Unique-name” ASOC
…
dictionary data
label
xml instance data
xml
label “gml.root-instance
ASOC
Unique-name” schema data
xml ASOC
label
ASOC label
Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved.
25 The GML Root Instance data for the single codestream case consists of a root GML feature
collection that contains codestream specific feature collections as members. These nested GML feature collections are as shown in Figure 5.
abc:RootFeatureCollection …
gml:featureMember abc:SpecificFeatureCollection
… gml:featureMember
gml:RectifiedGridCoverage …
gml:RectifiedGridCoverage gml:featureMember
gml:featureMember gml:FeatureInstance1
… gml:FeatureInstance1
gml:featureMember gml:featureMember
gml:FeatureInstance2 …
gml:FeatureInstance2 gml:featureMember
… abc:SpecificFeatureCollection
gml:featureMember abc:RootFeatureCollection
Image Metadata
Associated Features and
Annotation
Figure 5 — Single codestream root instance data in XML Box
The minimal structure for the Single Codestream = single image case is then as shown in Figure 6.
Figure 6 — Minimal packaging of GML for a single codestream
Note that the instance box SHALL contain the following: • GML Coverage Description, whose domain is a gml:RectifiedGrid .
The instance box MAY contain zero or more of the following: • Coverage metadata. This SHALL be referenced by the GML metaDataProperty from
the Coverage description.
asoc
“gml.data”
instance data xml
label “gml.root-instance
asoc asoc
label
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Copyright © 2006. Open Geospatial Consortium, Inc. All Rights Reserved.
• Image Annotations per the GML Annotation Schema described in Appendix A. Note that the instance box SHALL not contain dictionary definitions for Coordinate
Reference Systems, nor for Units of Measure. If these are to be supplied then an additional dictionary box shall be provided as in Figure 4.